4,254 research outputs found
AMSwarmX: Safe Swarm Coordination in CompleX Environments via Implicit Non-Convex Decomposition of the Obstacle-Free Space
Quadrotor motion planning in complex environments leverage the concept of
safe flight corridor (SFC) to facilitate static obstacle avoidance. Typically,
SFCs are constructed through convex decomposition of the environment's free
space into cuboids, convex polyhedra, or spheres. However, when dealing with a
quadrotor swarm, such SFCs can be overly conservative, substantially limiting
the available free space for quadrotors to coordinate. This paper presents an
Alternating Minimization-based approach that does not require building a
conservative free-space approximation. Instead, both static and dynamic
collision constraints are treated in a unified manner. Dynamic collisions are
handled based on shared position trajectories of the quadrotors. Static
obstacle avoidance is coupled with distance queries from the Octomap, providing
an implicit non-convex decomposition of free space. As a result, our approach
is scalable to arbitrary complex environments. Through extensive comparisons in
simulation, we demonstrate a improvement in success rate, an average
reduction in mission completion time, and an average
reduction in per-agent computation time compared to SFC-based approaches. We
also experimentally validated our approach using a Crazyflie quadrotor swarm of
up to 12 quadrotors in obstacle-rich environments. The code, supplementary
materials, and videos are released for reference.Comment: Submitted to ICRA 202
Therapeutic effect of hydroethanolic extract of Trianthema portulacastrum L. against N-Nitroso-N-Methylurea-induced mammary tumors in Wistar rats
This study evaluated the therapeutic action of hydroethanolic extract of Trianthema portulacastrum L. (TPE) on N-nitroso-N-methylurea (NMU)-induced mammary tumors in Wistar rats. A hydroethanolic was prepared and subjected to qualitative and quantitative phytochemical screening. After acclimatization, Wistar rats were divided into 4 groups of 6 rats each: Group A (vehicle control), Group B (TPE control), Group C (TPE treatment) and group D (NMU control). NMU (50 mg/kg body weight) was injected intraperitoneally at 50, 80 and 110 days of age. After the induction of palpable tumors,the rats were administered 200 mg/kg bw of TPE by oral gavage for 2 months. The treatment with TPE significantly (p<0.05) decreased tumor incidence, frequency, size and malignancy in comparison to the tumor-bearing rats that were not administered TPE. Immunohistochemical analysis revealed that TPE treatment significantly reduced the expression of PCNA, VEGF, ER-α and ER-β, and caused non-significant reductions in matrix metallopeptidase-9 (MMP-9). Caspase-3 expression significantly increased in TPE-treated rats in comparison with NMU-treated controls. The qRT-PCR resultsshowed PCNA and ER-β expression was down regulated and caspase-3 expression was up regulated in the TPE-treated group. The present study showed the in vivo therapeutic action of TPE extract on NMU-induced mammary tumors. TPE exhibited antitumor activity through its antiproliferative, antiangiogenic, pro-apoptotic, and estrogen receptor-modulatory properties
White-Light Emission from Annealed ZnO:Si Nanocomposite Thin Films
As grown ZnO:Si nanocomposites of different compositional ratios were
fabricated by thermal evaporation techniques. These films were subjected to
post deposition annealing under high vacuum at a temperature of
for 90min. The photoluminescence (PL) spectra of annealed samples have shown
marked improvements both in terms of intensity and broadening. For the first
time in ZnO:Si nanocomposite films we see huge UV, red and orange peaks at 310,
570 and 640nm. Structural and Raman analysis show formation of a Zn-Si-O shell
around ZnO nano clusters wherein on heating compound forms. The
new emissions are due to which completes white light spectrum.Comment: 9 figure
Genotypic correlation and path coefficient analysis for yield and yield contributing traits in released varieties of barley (Hordeum vulgare L.) under partially reclaimed saline sodic soil
This research sought to determine the correlations between grain yield and its contributing traits and to measure the direct and indirect effects on grain yield in barley. Sixty four released varieties were grown under par-tially reclaimed saline- sodic soil, under irrigated conditions during rabi 2010-11. The grain yield per plant showed highly significant and positive correlation with 1000 grain weight (0.517), plant height (0.460), length of main spike (0.459), fertile tillers per plant (0.385), and grains per main spike (0.366). On the basis of relationship of grain yield with yield contributing traits, we can select the best genotype and can be utilised in breeding program
Genetic variability and divergence analysis for yield and yield contributing traits in released varieties of barley (Hordeum vulgare L.) under partially reclaimed saline sodic soil
Genetic variability is the back bone of crop improvement programme, effectiveness of selection depends upon nature and magnitude of genetic variability present in the genetic material. The aim of the present study was that to identify the potential genotypes performing well under partially reclaimed saline- sodic soil (pH 8.6-8.9, EC = 4-4.2 dSm-1, ESP = > 15). Sixty four released varieties of barley collected from Directorate of Wheat Research, Karnal were grown during rabi season 2010-11, showing wide spectrum of variation for various characters. The characters studied were yield and yield contributing traits; namely plant height, days to maturity, fertile tillers / plant, length of main spike, grains per main spike, 1000-grains weight, grain yield per plant. The data on 7 characters was utilized for estimation of mean, range and least significant differences. The varieties RD-2552(8.52), HBL-276(8.35), RD- 2592(8.17), PL-419(8.15), Kedar(8.11), PL-751(8.10), JB-58(8.06), K-508(7.96) produced higher grain yield per plant and showed high to very high mean performance for several other yield component also. These selected varieties can be used in breeding program and can be recommended direct cultivation under partially reclaimed salinesodic soil
Participatory Pasture Development in Hot Arid Region of India
Livestock production is one of the main occupations of resource-poor and resource-rich people living in India’s arid regions, and common grazing lands have always played a major role in livestock based livelihood systems, as around 50% of animals depend on grazing (Misra et al, 2015). According to the National Sample Survey Organization, common property land resources constitute about 15% of the total geographical area of India, of which 23% is community pasture and grazing lands and 16% have been classified as village forests and woodlots (NSSO, 1999). At another level, India has the largest livestock population in the world, with 512 million head of livestock, many of them raised by small and marginal farmers who depend on grazing land to meet the fodder requirements of their animals (Anonymous, 2012). Traditionally, close link exists between livestock and common property resources (CPRs), as grazing is predominate feeding practice among the livestock keepers in hot arid region of India. This complex inter-relationship between CPRs, livestock and crops in arid and semi-arid production systems has contributed to the sustainability of dryland agriculture for generations (Misra et al., 2009). However, the typical scenario of community grazing lands has been one of gradually declining productivity due to overexploitation, and declining area due to privatization. Keeping this in view, Livestock Production Systems & Range Management Division and Krishi Vigyan Kendra (KVK) of Central arid Zone Research Institute (CAZRI), Jodhpur identified pasture development as a major thrust area for the hot arid zone of India. The interventions related to pasture development was carried out on a total of 88 ha common/private land in ten gram panchayat in two districts (Jodhpur and Nagur) of western Rajasthan during 2010-14 in collaboration with local farming communities, NGOs and Goushala
Gravitational Collapse of Inhomogeneous Dust in (2+1) Dimensions
We examine the gravitational collapse of spherically symmetric inhomogeneous
dust in (2+1) dimensions, with cosmological constant. We obtain the analytical
expressions for the interior metric. We match the solution to a vacuum
exterior. We discuss the nature of the singularity formed by analyzing the
outgoing radial null geodesics. We examine the formation of trapped surfaces
during the collapse.Comment: Accepted for publication in CQ
The joy stick technique: an easy, reliable, safe and cost effective, technique in closed reduction and percutaneous fixation of supracondylar fracture of the humerus in children
Background: Supra condylar fractures of humerus account for approximately 16% of all pediatric fractures. This produces an extension type fracture in 97–99%. Flexion type accounting for 1-3%. This often causes significant morbidity due to malunion (gun-stock deformity) reported in 12 to 20%, while neurovascular complications and compartment syndrome is documented in worse scenarios.Methods: A prospective study was conducted with 24 cases of supracondylar humerus fracture between June 2017 to June 2021. Both males and females aged 3 years to 12 years, within 5 days of injury, with modified Gartland’s type III and type IV, without compartment syndrome were included and followed up for 6 months to one year. The fracture was closely reduced using a 2-2.5 mm k-wire (joystick) in proximal fragment placed 5-7 cm proximal to fracture line and fixed with multiple percutaneous pinning under C-arm. All the patients were followed for rate of union and functional outcome using Flynn’s criteria.Results: All the 24 cases were managed by closed maneuver with the help of a joy stick. This reduces the surgical time and stress, preventing opening of fracture. Outcome was assessed in each follow up using Flynn’s criteria. 87.5% of patients had good to excellent outcomes.Conclusions: Our results demonstrate that good functional outcomes are expected in supracondylar fracture regardless of age at injury, sex, weight, side of extremity provided satisfactory reduction by closed technique with help of joy stick. This simple technique reduces surgical stress, duration of surgery and also minimizes the C-arm exposure
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